If you are lost or if you get lost, you do not know where you are or are unable to find your way.
Barely had I set foot in the street when I realized I was lost.
我刚走上那条街就发现自己迷路了。
If something is lost, or gets lost, you cannot find it, for example, because you have forgotten where you put it.
a lost book.
一本丢失的书。
He was scrabbling for his pen, which had got lost somewhere under the sheets of paper.
他正在翻找埋在纸堆下的钢笔。
If you feel lost, you feel very uncomfortable because you are in an unfamiliar situation.
Of the funeral he remembered only the cold, the waiting, and feeling very lost.
有关那次葬礼,他只记得当时很冷,等了很长时间,而且感到很迷惘。
If you describe something as lost, you mean that you no longer have it or it no longer exists.
their lost homeland.
他们失去的家园。
The sense of community is lost.
团体意识不复存在。
You use lost to refer to a period or state of affairs that existed in the past and no longer exists.
He seemed to pine for his lost youth.
他似乎在怀念他逝去的青春。
They are links to a lost age.
他们是连接一个逝去年代的纽带。
If something is lost, it is not used properly and is considered wasted.
Smith is not bitter about the lost opportunity to compete in the games.
史密斯没有因为错过参赛机会而痛苦。
Lost is the past tense and past participle of lose.